How Artificial Sweeteners in Diet Soda Can Affect Your Health

Artificial sweeteners were developed over a century ago as a food additive to provide sweetness without the caloric content of sugar. A zero-calorie, guilt-free option - or so they say. The United States Food and Drug Administration (FDA) has approved five artificial sweeteners:¹

1. Aspartame
2. Saccharin
3. Acesulfame potassium
4. Neotame
5. Sucralose

Aspartame is a white, odorless powder found in many processed foods. It is 200 times sweeter than regular sugar with many studies showing that aspartame has been linked to the exacerbation of diabetes, obesity, headache, seizures, depression, and arthritis, to name a few.² While aspartame does not directly raise or lower blood sugar and insulin (no glycemic effects), studies show it can be harmful.

Tip from an MD: Be sure to check the ingredients list on the back of food labels. In the United States, it is required by law to list if aspartame is added. If so, place it back on the shelf!

Saccharin is 300 - 500 times more potent than sugar and passes through the GI system undigested. This led one research study to show that saccharin can actually alter our natural gut flora (healthy bacteria in the gastrointestinal tract).³ While some studies show that it does lower insulin levels and improves blood sugar control, these were only in mice models. In humans, saccharin consumption has been linked to the increased accumulation of body fat, despite diet and exercise. 

Tip from an MD: Saccharin tends to be in food and drinks labeled diet, sugar-free, or light. Fountain Diet Coca-Cola contains a mixture of aspartame and saccharin, while store bought Diet Coke uses aspartame exclusively. Many states have filed class action suits against Coca-Cola for not stating this.⁴

Acesulfame potassium was approved in 2003, is 200 times sweeter than sucrose, and bears no glycemic effects. It also passes through the body unmetabolized and is excreted by the kidneys.⁵

Neotame was approved in 2002 for large scale food manufacturing and is not available commercially. Remarkably, this chemical is 7,000 times sweeter than sucrose!⁶

Sucralose is a more natural derivative of sucrose. In human studies, sucralose overall showed no statistically significant differences between the study and control groups when measuring participants fasting plasma glucose and A1c.⁷

Tip from an MD: Splenda is a common sweetener that uses sucralose. It can be added to diet sodas, chewing gum, and desserts.

<p class="pro-tip"><strong>Learn about </strong> <a href="/blog/sugar-substitutes-and-artificial-sweeteners-part-3">using artificial sweeteners responsibly</a>.</p>

How Diet Soda Affects Insulin

Studies show that drinking diet soda alone does not directly cause diabetes,⁸ nor does it directly raise insulin levels.⁹ When combined with other food or glucose, however, those who consume diet soda have higher levels of insulin and what is called glucagon-like peptide 1 (GLP-1).¹⁰ This is important for several reasons.

GLP-1 is a hormone that helps to increase levels of insulin. Many medications used to treat diabetics are GLP-1 agonists, for those with insulin resistance. Diet soda increases levels of GLP-1.¹¹ More studies will need to be done to determine the clinical significance of this, and what the health ramifications are, but suffice it to say that diet soda does directly impact our digestive hormones, and should be avoided in the setting of diabetes.